I. Field
The present disclosure relates generally to communication, and more specifically to transmission techniques for a wireless communication system.
II. Background
Wireless communication systems are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, etc. These wireless systems may be multiple-access systems capable of supporting multiple users by sharing the available system resources. Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal FDMA (OFDMA) systems, and Single-Carrier FDMA (SC-FDMA) systems.
In a wireless communication system, a base station may serve many users. These users may observe different channel conditions (e.g., different fading, multipath, and interference effects) and may achieve different received signal-to-noise-and-interference ratios (SINRs). Furthermore, a given user may observe frequency selective fading and may achieve different SINRs across the system bandwidth. It is desirable to support transmissions for different users with different channel conditions such that good performance can be achieved for all of the users.